A national policy to address the problem of lead contamination of drinking water will be published in the coming months, Irish Water has said.

Tests on drinking water in Dublin homes up to last December showed lead levels far in excess of legal limits, with one house in Raheny, tested last July, producing a reading more than 80 times the maximum “safe” limit.

Irish Water said the water it produces at treatment plants does not contain lead, and lead pipes in the mains distribution network have been replaced.

However, this does not mean lead had been eliminated from the public pipes. For many years lead was used in the manufacture of supply pipes known as “service connections” running from the mains to the property, and not all these pipes have been replaced.

In addition, up to 30,000 homes which are supplied off shared backyard pipes, typically in estates built from the 1940s to the 1960s, have lead service pipes. Irish Water “accepts responsibility for these mains” and has a three- to five-year replacement plan.

However, the company said replacing the public connection and shared service pipes will not solve the lead problem. “Surveys in parts of Dublin and elsewhere have demonstrated that replacing the public side connection only is not effective in meeting the standard for lead.”

This is because lead was standard in domestic plumbing up to the 1970s. In fact, Irish Water says, any property of that age or older “should be suspected” of having lead plumbing.

Lead is not just a Dublin problem. Last year the Environmental Protection Agency prosecuted Irish Water and Kerry County Council for failing to replace lead mains in a Tralee housing estate, where 43 micrograms of lead per litre of water was detected. The legal limit is 10 micrograms.

But the capital’s housing stock has a large proportion of pre-1970s properties, not only in the city, but in outer suburbs such as Raheny, where up to 825 micrograms of lead per litre was found.

Public communication about lead contamination has been less than impressive. Irish Water has not addressed the issues in its advertising or leafleting of homes.

The replacement of lead pipes is not part of the “first fix free” programme, where Irish Water will repair leaks to pipes outside the hall door, but within the property – typically under the front garden. Though if the broken pipe happens to be lead it will be replaced. Rather the onus appears to be on the homeowner to replace the pipes on their side of the garden gate, for Irish Water to follow suit.

“Where a householder elects to replace the private side lead piping, most local authorities had a policy of replacing the public lead pipe also at the same time and Irish Water intends to continue this practice.”

The HSE/EPA advice is: “If you suspect you may have lead pipes, look for them.” Their joint paper does say what to look for: unpainted lead pipes are “dull grey” and “soft” and may be found under the sink or under the stairs. Outside at the stopcock the householder can “scrape the surface gently with a knife” to check for lead.

If lead is found drinking water should be tested and the householder should contact their supplier for advice. “The best way of dealing with lead in your drinking water is to replace all lead pipes and plumbing,” the HSE/EPA says.

“Alternatively, running the water at the cold tap in the kitchen before using it for drinking or cooking can sometimes lower the level of lead. The amount of water you need to run off will vary from house to house. The only way to know the right amount is by testing and retesting the water. If after running the water, the level of lead stays above 10 micrograms per litre you should use safe drinking water from some other source.”